1. Field of the Invention
The present invention relates to a connector of a communication cable and a communication cable and particularly to a plug connector of a communication cable and a receptacle connector which are specified by a data communication standard such as Universal Serial Bus (USB).
2. Description of Related Art
As main equipment with a built-in computer become highly functional, peripheral equipment such as a printer, an input device and a hard disk drive (HDD) become more functional accordingly. A computer and peripheral equipment are connected through a communication cable or the like according to a prescribed communication standard. Though various communication standards have been proposed and used, peripheral equipment connection based on the USB standard is widely used recently.
The USB standard defines two types: A type plug connector and receptacle connector, and B type plug connector and receptacle connector.
In the following description, a plug connector and a receptacle connector are referred to collectively as a “connector” where they are not distinguished, and referred to simply as a “plug” and a “receptacle” respectively, where distinguished. Further, where the two different types of connectors are distinguished, they are abbreviated as “A-” and “B-” such as an A-connector and a B-plug.
In the USB standard, a conventional A-plug 901 shown in FIG. 16 corresponds with a conventional A-receptacle 902 shown in FIG. 17. The A-plug 901 is inserted into the A-receptacle 902, so that terminals 911 to 914 and terminals 921 to 924, which are respectively placed in the A-plug 901 and the A-receptacle 902, are electrically connected to each other. Further, a conventional B-plug 903 shown in FIG. 18 corresponds with a conventional B-receptacle 904 shown in FIG. 19. The B-plug 903 is inserted into the B-receptacle 904, so that terminals 931 to 934 and terminals 941 to 944, which are respectively placed in the B-plug 903 and the B-receptacle 904, are electrically connected to each other.
When connecting equipment which requires high power consumption, such a conventional connector of a communication cable is mated with a power cable or a battery rather than a communication cable to thereby increase power supply using a different means from a communication cable. Therefore, for equipment which cannot be connected with a different means from a communication cable, power supply is limited.
Further, for equipment which communicates with non-USB standard, it is necessary to use a different means from a standardized communication cable. Therefore, equipment which cannot be connected with the different communication means may be incapable of communication.
To overcome such drawbacks, a connector of a communication cable for additional power transmission is disclosed in Japanese Unexamined Patent Application Publication Nos. 2003-197318 and 2003-197302, for example. Those techniques provides an additional power supply terminal on an insulating resin where power supply terminals and signal terminals are formed, thereby enabling additional power transmission.
Because the shape and position of an existing terminal are defined by the standard, it is difficult to add a new terminal due to space limitation. Further, if there are connectors and receptacles having additional power supply terminals in which a power supply terminal and a GND terminal has the same shape with reverse polarity, for example, wrong insertion is likely to occur to cause short-circuit or failure in appropriate signal transmission.
As described in the foregoing, a conventional communication cable is incompatible with the transmission of additional power supply, a signal outside of the USB standard, and so on.